Riko Muranaka

is a medical doctor, journalist and recipient of the 2017 John Maddox Prize for fighting to reduce cervical cancer and countering misinformation about the human papilloma virus (HPV) vaccine dominating the Japanese media, despite facing safety threats.

Muranaka is part-time lecturer at the Japan Kyoto University School of Medicine. As of 2019, she lives in Germany.

Lawsuit

In 2016, Muranaka wrote in the Wedge magazine about research done by Shinshu University neurologist Shuichi Ikeda, alleging that some results to demonstrate a link between an HPV vaccine and brain cancer in mouse had been fabricated, resulting in a slander lawsuit. While Japanese's Health Ministry stated that Ikeda's results "have not proven anything about whether the symptoms that occurred after HPV vaccination were caused by the HPV vaccine," the court ruled that evidence of fabrication was absent. The university investigation on Ikeda's work concluded that he did not commit scientific misconduct, but that conclusions may have been overstated, then released a statement, including that the research did not conclusively provide a link in relation to vaccine safety. Muranaka lost the slander case. Wedge magazine had to retract claims of fabrication from the article with both needing to pay for damages.

In support of Muranaka, Nobel laureate Tasuku Honjo submitted an expert opinion during the appeals process, criticizing the scientific basis of Ikeda's study and emphasizing the importance of reproducibility in biomedical research.

Muranaka intends to appeal, also stating that she needs to win the lawsuit for science and that the court case was still an opportunity to make friends and gain recognition despite its negative aspects.

Vaccination against human papillomavirus The WHO has evaluated the effectiveness and safety of the vaccine against human papilloma virus (HPV) concluding that it is extremely safe and that it is not related to the adverse effects attributed to it.

At 2016, 79 out of almost 200 countries have HPV vaccine programs for girls and adolescents.

However, Japan stopped recommending vaccination despite the fact that its own technical committees found no relationship with the alleged adverse effects falsely attributed to this vaccine, and as a consequence, vaccination coverage fell to levels close to zero, not seen in any other country. In November 2021, the Ministry of Health, Labour, and Welfare of Japan finally resumed active recommendations of the HPV vaccine.

Works